PCW/PHEOS-WCA: Quasi-geostationary Arctic measurements for weather, climate and air quality from highly eccentric orbits

The PCW (Polar Communications and Weather) mission is a dual satellite mission with each satellite in a highly eccentric orbit with apogee ~42,000 km and a period (to be decided) in the 12–24 hour range to deliver continuous communications and meteorological data over the Arctic and environs. Such as satellite duo can give 24×7 coverage over the Arctic. The operational meteorological instrument is a 21-channel spectral imager similar to the Advanced Baseline Imager (ABI). The PHEOS-WCA (weather, climate and air quality) mission is intended as an atmospheric science complement to the operational PCW mission. The target PHEOS-WCA instrument package considered optimal to meet the full suite of science team objectives consists of FTS and UVS imaging sounders with viewing range of ~4.5° or a Field of Regard (FoR) ~ 3400×3400 km 2 from near apogee. The goal for the spatial resolution at apogee of each imaging sounder is 10×10 km 2 or better and the goal for the image repeat time is targeted at ~2 hours or better. The FTS has 4 bands that span the MIR and NIR with a spectral resolution of 0.25 cm −1 . They should provide vertical tropospheric profiles of temperature and water vapour in addition to partial columns of many other gases of interest for air quality. The two NIR bands target columns of CO 2 , CH 4 and aerosol optical depth (OD). The UVS is an imaging spectrometer that covers the spectral range of 280–650 nm with 0.9 nm resolution and targets the tropospheric column densities of O 3 and NO 2 and several other Air Quality (AQ) gases as well the Aerosol Index (AI).